A dielectric-defined lateral heterojunction in a monolayer semiconductor

Abstract

Owing to their low dimensionality, two-dimensional semiconductors, such as monolayer molybdenum disulfide, have a range of properties that make them valuable in the development of nanoelectronics. For example, the electronic bandgap of these semiconductors is not an intrinsic physical parameter and can be engineered by manipulating the dielectric environment around the monolayer. Here we show that this dielectric-dependent electronic bandgap can be used to engineer a lateral heterojunction within a homogeneous MoS2 monolayer. We visualize the heterostructure with Kelvin probe force microscopy and examine its influence on electrical transport experimentally and theoretically. We observe a lateral heterojunction with an approximately 90 meV band offset due to the differing degrees of bandgap renormalization of monolayer MoS2 when it is placed on a substrate in which one segment is made from an amorphous fluoropolymer (Cytop) and another segment is made of hexagonal boron nitride. This heterostructure leads to a diode-like electrical transport with a strong asymmetric behaviour.

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Fig. 1: Engineering 2D heterojunctions through dielectric-dependent bandgap renormalization.
Fig. 2: Current–voltage characteristics of a MoS2 heterojunction device.
Fig. 3: KPFM characterization of the MoS2 heterojunction formation from differences in the degree of local dielectric screening.
Fig. 4: Simulation results of the energy band bending at the 2D heterojunction.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request

References

  1. 1.

    Wang, Q. H., Kalantar-Zadeh, K., Kis, A., Coleman, J. N. & Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol. 7, 699–712 (2012).

    Article  Google Scholar 

  2. 2.

    Butler, S. Z. et al. Progress, challenges, and opportunities in two-dimensional materials beyond graphene. ACS Nano 7, 2898–2926 (2013).

    Article  Google Scholar 

  3. 3.

    Xia, F., Wang, H., Xiao, D., Dubey, M. & Ramasubramaniam, A. Two-dimensional material nanophotonics. Nat. Photon. 8, 899–907 (2014).

    Article  Google Scholar 

  4. 4.

    Radisavljevic, B. & Kis, A. Mobility engineering and a metal–insulator transition in monolayer MoS2. Nat. Mater. 12, 815–820 (2013).

    Article  Google Scholar 

  5. 5.

    Mak, K. F., McGill, K. L., Park, J. & McEuen, P. L. The valley Hall effect in MoS2 transistors. Science 344, 1489–1492 (2014).

    Article  Google Scholar 

  6. 6.

    Cui, X. et al. Multi-terminal transport measurements of MoS2 using a van der Waals heterostructure device platform. Nat. Nanotechnol. 10, 534–540 (2015).

    Article  Google Scholar 

  7. 7.

    Fiori, G. et al. Electronics based on two-dimensional materials. Nat. Nanotechnol. 9, 768 (2014).

    Article  Google Scholar 

  8. 8.

    Jariwala, D., Sangwan, V. K., Lauhon, L. J., Marks, T. J. & Hersam, M. C. Emerging device applications for semiconducting two-dimensional transition metal dichalcogenides. ACS Nano 8, 1102–1120 (2014).

    Article  Google Scholar 

  9. 9.

    Chhowalla, M., Jena, D. & Zhang, H. Two-dimensional semiconductors for transistors. Nat. Rev. Mater. 1, 16052 (2016).

    Article  Google Scholar 

  10. 10.

    Qiu, D. Y., da Jornada, F. H. & Louie, S. G. Optical spectrum of MoS2: many-body effects and diversity of exciton states. Phys. Rev. Lett. 111, 216805 (2013).

    Article  Google Scholar 

  11. 11.

    Chernikov, A. et al. Exciton binding energy and nonhydrogenic Rydberg series in monolayer WS2. Phys. Rev. Lett. 113, 076802 (2014).

    Article  Google Scholar 

  12. 12.

    Qiu, D. Y., da Jornada, F. H. & Louie, S. G. Screening and many-body effects in two-dimensional crystals: Monolayer MoS2. Phys. Rev. B 93, 235435 (2016).

    Article  Google Scholar 

  13. 13.

    Ugeda, M. M. et al. Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor. Nat. Mater. 13, 1091–1095 (2014).

    Article  Google Scholar 

  14. 14.

    Ye, Z. et al. Probing excitonic dark states in single-layer tungsten disulphide. Nature 513, 214–218 (2014).

    Article  Google Scholar 

  15. 15.

    Zhang, C., Johnson, A., Hsu, C.-L., Li, L.-J. & Shih, C.-K. Direct imaging of band profile in single layer MoS2 on graphite: Quasiparticle energy gap, metallic edge states, and edge band bending. Nano. Lett. 14, 2443–2447 (2014).

    Article  Google Scholar 

  16. 16.

    Zhu, B., Chen, X. & Cui, X. Exciton binding energy of monolayer WS2. Sci. Rep. 5, 9218 (2015).

    Article  Google Scholar 

  17. 17.

    Hill, H. M. et al. Observation of excitonic Rydberg states in monolayer MoS2 and WS2 by photoluminescence excitation spectroscopy. Nano. Lett. 15, 2992–2997 (2015).

    Article  Google Scholar 

  18. 18.

    Zhang, Y. et al. Electronic structure, surface doping, and optical response in epitaxial WSe2 thin films. Nano. Lett. 16, 2485–2491 (2016).

    Article  Google Scholar 

  19. 19.

    Komsa, H.-P. & Krasheninnikov, A. V. Effects of confinement and environment on the electronic structure and exciton binding energy of MoS2 from first principles. Phys. Rev. B 86, 241201 (2012).

    Article  Google Scholar 

  20. 20.

    Stier, A. V., Wilson, N. P., Clark, G., Xu, X. & Crooker, S. A. Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields. Nano. Lett. 16, 7054–7060 (2016).

    Article  Google Scholar 

  21. 21.

    Ryou, J., Kim, Y.-S., Kc, S. & Cho, K. Monolayer MoS2 bandgap modulation by dielectric environments and tunable bandgap transistors. Sci. Rep. 6, 29184 (2016).

    Article  Google Scholar 

  22. 22.

    Raja, A. et al. Coulomb engineering of the bandgap and excitons in two-dimensional materials. Nat. Commun. 8, 15251 (2017).

    Article  Google Scholar 

  23. 23.

    Cho, Y. & Berkelbach, T. C. Environmentally sensitive theory of electronic and optical transitions in atomically-thin semiconductors. Phys. Rev. B 97, 041409(R) (2018).

    Article  Google Scholar 

  24. 24.

    Bradley, A. J. et al. Probing the role of interlayer coupling and Coulomb interactions on electronic structure in few-layer MoSe2 nanostructures. Nano. Lett. 15, 2594–2599 (2015).

    Article  Google Scholar 

  25. 25.

    Andersen, K., Latini, S. & Thygesen, K. S. Dielectric genome of van der Waals heterostructures. Nano. Lett. 15, 4616–4621 (2015).

    Article  Google Scholar 

  26. 26.

    Latini, S., Olsen, T. & Thygesen, K. S. Excitons in van der Waals heterostructures: the important role of dielectric screening. Phys. Rev. B 92, 245123 (2015).

    Article  Google Scholar 

  27. 27.

    Olsen, T., Latini, S., Rasmussen, F. & Thygesen, K. S. Simple screened hydrogen model of excitons in two-dimensional materials. Phys. Rev. Lett. 116, 056401 (2016).

    Article  Google Scholar 

  28. 28.

    Nonnenmacher, M., O’Boyle, M. P. & Wickramasinghe, H. K. Kelvin probe force microscopy. Appl. Phys. Lett. 58, 2921–2923 (1991).

    Article  Google Scholar 

  29. 29.

    Melitz, W., Shen, J., Kummel, A. C. & Lee, S. Kelvin probe force microscopy and its application. Surf. Sci. Rep. 66, 1–27 (2011).

    Article  Google Scholar 

  30. 30.

    Tosun, M. et al. MoS2 heterojunctions by thickness modulation. Sci. Rep. 5, 10990 (2015).

    Article  Google Scholar 

  31. 31.

    Forsythe, C. et al. Band structure engineering of 2D materials using patterned dielectric superlattices. Nat. Nanotechnol. 13, 566–571 (2018).

  32. 32.

    Li, L. et al. Direct observation of the layer-dependent electronic structure in phosphorene. Nat. Nanotechnol. 12, 21–25 (2016).

    Article  Google Scholar 

  33. 33.

    Qiu, D. Y., da Jornada, F. H. & Louie, S. G. Environmental screening effects in 2D materials: renormalization of the bandgap, electronic structure, and optical spectra of few-layer black phosphorus. Nano. Lett. 17, 4706–4712 (2017).

    Article  Google Scholar 

  34. 34.

    Geick, R., Perry, C. H. & Rupprecht, G. Normal modes in hexagonal boron nitride. Phys. Rev. 146, 543–547 (1966).

    Article  Google Scholar 

  35. 35.

    Liu, B. et al. Engineering bandgaps of monolayer MoS2 and WS2 on fluoropolymer substrates by electrostatically tuned many-body effects. Adv. Mater. 28, 6457–6464 (2016).

    Article  Google Scholar 

  36. 36.

    Dean, C. R. et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotechnol. 5, 722–726 (2010).

    Article  Google Scholar 

  37. 37.

    Sze, S. M. & Ng, K. K. Physics of Semiconductor Devices (Wiley, Hoboken, 2007).

  38. 38.

    Sedra, A. S. & Smith, K. C. Microelectronic Circuits 5th edn (Oxford Univ. Press, New York, 2004).

  39. 39.

    Hybertsen, M. S. & Louie, S. G. Electron correlation in semiconductors and insulators: band gaps and quasiparticle energies. Phys. Rev. B 34, 5390–5413 (1986).

    Article  Google Scholar 

  40. 40.

    Deslippe, J. et al. BerkeleyGW: A massively parallel computer package for the calculation of the quasiparticle and optical properties of materials and nanostructures. Comp. Phys. Comm. 183, 1269–1289 (2012).

    Article  Google Scholar 

  41. 41.

    da Jornada, F. H., Qiu, D. Y. & Louie, S. G. Nonuniform sampling schemes of the Brillouin zone for many-electron perturbation-theory calculations in reduced dimensionality. Phys. Rev. B 95, 035109 (2017).

    Article  Google Scholar 

  42. 42.

    Jin, C. et al. Imaging of pure spin–valley diffusion current in WS2–WSe2 heterostructures. Science 360, 893–896 (2018).

    Article  Google Scholar 

  43. 43.

    Alam, K. & Lake, R. K. Monolayer MoS2 transistors beyond the technology road map. IEEE Trans. Elect. Dev. 59, 3250–3254 (2012).

    Article  Google Scholar 

  44. 44.

    Desai, S. B. et al. MoS2 transistors with 1-nanometer gate lengths. Science 354, 99–102 (2016).

    Article  Google Scholar 

  45. 45.

    Das, S., Chen, H.-Y., Penumatcha, A. V. & Appenzeller, J. High performance multilayer MoS2 transistors with scandium contacts. Nano. Lett. 13, 100–105 (2013).

    Article  Google Scholar 

  46. 46.

    Giannazzo, F., Fisichella, G., Piazza, A., Agnello, S. & Roccaforte, F. Nanoscale inhomogeneity of the Schottky barrier and resistivity in MoS2 multilayers. Phys. Rev. B 92, 081307 (2015).

    Article  Google Scholar 

  47. 47.

    Cui, X. et al. Low-temperature Ohmic contact to monolayer MoS2 by van der Waals bonded Co/h-BN electrodes. Nano. Lett. 17, 4781–4786 (2017).

    Article  Google Scholar 

  48. 48.

    Liu, Y. et al. Approaching the Schottky–Mott limit in van der Waals metal–semiconductor junctions. Nature 557, 696–700 (2018).

    Article  Google Scholar 

  49. 49.

    Maier, G. Low dielectric constant polymers for microelectronics. Prog. Polym. Sci. 26, 3–65 (2001).

    Article  Google Scholar 

  50. 50.

    Stoppa, M. & Chiolerio, A. Wearable electronics and smart textiles: a critical review. Sensors 14, 11957 (2014).

    Article  Google Scholar 

  51. 51.

    Levendorf, M. P. et al. Graphene and boron nitride lateral heterostructures for atomically thin circuitry. Nature 488, 627–632 (2012).

    Article  Google Scholar 

  52. 52.

    Liu, Z. et al. In-plane heterostructures of graphene and hexagonal boron nitride with controlled domain sizes. Nat. Nanotechnol. 8, 119–124 (2013).

    Article  Google Scholar 

  53. 53.

    Castellanos-Gomez, A. et al. Deterministic transfer of two-dimensional materials by all-dry viscoelastic stamping. 2D Mater. 1, 011002 (2014).

    Article  Google Scholar 

  54. 54.

    Lee, G.-H. et al. Flexible and transparent MoS2 field-effect transistors on hexagonal boron nitride–graphene heterostructures. ACS Nano 7, 7931–7936 (2013).

    Article  Google Scholar 

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Acknowledgements

We thank M. Asta, J. Yao and S. Kahn for helpful discussions. This work was primarily supported by the Center for Computational Study of Excited State Phenomena in Energy Materials, which is funded by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05CH11231, as part of the Computational Materials Sciences Program. The device fabrication is supported by the National Science Foundation EFRI Program (EFMA-1542741). This research used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231, and the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1548562. H.K. was supported by the Deutsche Forschungsgemeinschaft (KL 2961/1-1). C.S.O. acknowledges support from the Singapore National Research Foundation (Clean Energy) PhD Scholarship. R.K. was supported by the JSPS Overseas Research Fellowship Program. S.T. acknowledges support from a NSF DMR 1552220 NSF CAREER award. Growth of hexagonal boron nitride crystals was supported by the Elemental Strategy Initiative conducted by the MEXT, Japan and a Grant-in-Aid for Scientific Research on Innovative Areas ‘Science of Atomic Layers’ from JSPS.

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Contributions

F.W., M.I.B.U. and H.K. conceived the project and designed the experiments. M.I.B.U. and H.K. performed sample preparation, device fabrication, electrical transport measurements and data analysis. W.Z., M.I.B.U. and S.W. performed KPFM measurements. M.I.B.U. conducted optical spectroscopy. R.K., S.Z. and A.Z. contributed to the device fabrication process. F.W., M.I.B.U. and H.K. simulated the energy band diagram of the heterojunction. C.S.O., F.H.d.J. and D.Y.Q. performed GW calculations on and, together with S.G.L., did the analyses of the quasiparticle band structures. H.C., H.L. and S.T. grew the MoS2 single crystal. K.W. and T.T. grew the hBN single crystal. F.W., S.G.L. and A.Z. supervised the project.

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Correspondence to Feng Wang.

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Supplementary Notes 1–4 and Supplementary Figures 1–10

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Utama, M.I.B., Kleemann, H., Zhao, W. et al. A dielectric-defined lateral heterojunction in a monolayer semiconductor. Nat Electron 2, 60–65 (2019). https://doi.org/10.1038/s41928-019-0207-4

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